The present invention relates to novel metastin derivatives and their use.
It is well known that cancer is one of the leading causes of death throughout the world. Recent strategies for treating cancer have focussed on metastasis. In this process, cancer cells dissociate from malignant tumors and then invade surrounding or distant tissue, where they proliferate. It has been found that the product from the gene known as KiSS-1 suppresses metastasis of human melanomas and breast carcinomas.
The KiSS1 peptide was originally identified as being differentially up-regulated in C8161 melanoma cells that have been rendered nonmetastatic by microcell-mediated transfer of human chromosomes. (Lee, J H et al., J Natl Cancer Inst 1996, 88, 1731-7). It has been found that transfection of KiSS1 into human melanoma and breast carcinoma cells prevents these cells from metastasizing without cellular proliferation. (Lee, J H et al., Cancer Res 1997, 57, 2384-72). Furthermore, the KISS1 gene product has been shown to repress 92-kDa type4 collagenase (MMP-9) expression by effecting reduced NF-kB binding to the promoter. (Yan, C. et al., J Biol Chem 2001, 276, 1164-72). The KISS1 gene product was found to be expressed in normal human placenta, testis, brain, pancreas and liver. (Muir, A I et al., J Biol Chem 2001, 276, 28969-75).
KiSS-1 encodes a 145-amino acid residue peptide, which is further processed to a final 54-amino acid peptide with C-terminal amidation. The 54 amino acid peptide called xe2x80x9cmetastinxe2x80x9d is the ligand to a G-protein-coupled orphan receptor known as OT7T175 or AXOR12. (Muir, A I. et al., supra; Ohtaki, T, et al., Nature 2001, 411, 613-7; Hori, A. et al., Biochem Biophys Res Commun 2001, 286, 958-63; Kotani, M. et al., J Biol Chem 2001, 276, 34631-6). This receptor has a high degree of homology to the rat orphan heptahelical receptor GPR54 (Lee, D K. et al., FEBS Lett 1999, 446, 103-7), (81% amino acid identity), which suggest that these two receptors are orthologs. Metastin enhanced the expression and activity of focal adhesion kinase, and attenuates pulmonary metastasis of hOT7T175 transfected B16-BL6 melanomas in vivo. (Ohtaki, T. et al., supra.) Metastin was also found to inhibit chemotaxis and invasion of hOT7T175 transfected Chinese hamster ovary (CHO) cells in vitro with activation of phospholipase C, arachidonic acid relase, and phosphorylation of ERK. (Hori, A. et al., supra and Kotani, M. et al., supra.) Although these pathways typically induce cellular proliferation, change in cell growth was not observed.
The KiSS1 gene is located on human chromosome1q32-q41. (West, A. et al., Genomics 1998, 54, 145-8). However, evidence from subsequent experiments suggests that the expression of KiSS1 is very likely to bc regulated by a gene or genes located in the 40-cM region between 6q16.3-q23. (Lee, J H. et al., J Natl Cancer Inst 1996, 88, 1731-7). In pancreatic cancer, losses of 6q, 8p, 9p, 17p, and 18q were frequently observed and those alterations tend to cause lymph node metastasis and distant metastasis, which suggests the existence of a metastasis suppressor gene or genes responsible for pancreatic carcinoma metastasis on these regions. (Rigaud, G, et al., Int J Cancer 2000, 88, 772-7 ; Yatsuoka, T. et al., Am J Gastroenterol 2000, 95, 2080-5; Harada, T. et al., Oncology 2002, 62, 251-8). These suggest that pancreatic cancer is associated with down regulation of metastin expression. Moreover, in other cancers such as ovarian and breast carcinoma as well as thyroid papillary cancer, overexpression of the metastin receptor, hOT7T175, has been demonstrated, as compared to normal tissue (Muir, A I. et al, supra; Ohtaki, T. et al., supra), although metastin itself is less frequently overexpressed in the tumor tissue. (Lee, J H.et al, supra). The expression of KiSS-1, i.e., metastin production, and the expression of its receptor in pancreatic cancer has not yet been studied. Similarly, the effects of metastin on the movement of cancer cells that endogenously express the receptor have not been investigated.
These findings indicate that KISS1-hOT7T175 acts as a metastasis suppressor system. Because metastin inhibits metastasis of cancer cells without affecting cellular growth properties in normal cells, it is desirable to target the metastin receptors for cancer therapy. Thus, it would be desirable to have compounds that bind metastin receptors, suppress cancer metastasis and/or suppress cancer proliferation. Furthermore, it would be useful to have compounds that have metastasis suppressing activity and that can be used to treat acute or chronic pancreatitis or pancreatic cancer.
WO00/24890 discloses human metastin, WO01/75104 discloses mouse or rat metastin and WO02/85399 discloses a sustained release preparation comprising metastin. These references disclose that metastin can suppress cancer metastasis. However, it is desirable to develop compounds that suppress cancer metastasis and cancer proliferation and that are useful as therapeutic agents for the treatment of cancers.
The present inventors found that by making certain modifications to peptides corresponding to, or analogous to, a portion of the metastin amino acid sequence, the resulting derivatives are stable and exhibit outstanding cancer metastasis inhibiting activity and cancer proliferation inhibiting activity.
The present invention provides a metastin derivative represented by the formula:
X-AA1-AA2-AA3-AA4-Z (I)
wherein X is a group represented by the formula: 
wherein Y is a group represented by the formula: 
wherein R1, R2,R3 and R4 are each selected from a hydrogen atom or a C1-6 alkyl group;
W1 and W2 are each selected from a hydrogen atom, a C1-6alkyl group, a C6-14 aryl group or a heterocyclic group;
R is represented by the formula: 
n is 0,1 or 2;
AA1 is a natural or unnatural aromatic amino acid;
AA2 is Gly, Ala, Pro or Pic;
AA3 is an aliphatic amino acid;
AA4 is a basic amino acid or citrulline;
Z is selected from:
(i) a natural or unnatural aromatic amino acid, or an amide thereof, or an ester thereof,
(ii) a group represented by the formula: 
xe2x80x83wherein n1 is 0, 1 or 2
(iii) a group represented by the formula: 
xe2x80x83wherein n2 is 0, 1 or 2, or
(iv) a group represented by the formula: 
wherein n2 is 0,1 or 2, or a salt thereof;
The present invention also provides a metastin derivative (I) as defined above, which is 4-[N,N-Bis(2-pyridylmethyl)aminomethyl]benzoyl-Phe-Gly-Leu-Arg-Trp-NH2 (FM052a) (SEQ ID NO: 4), 4-(guanidinomethyl)benzoyl-Phe-Gly-Leu-Arg-Trp-NH2 (FM053) (SEQ ID NO: 3) or a salt thereof.
The present invention also provides a pro-drug of a metastin derivative (I) as defined above or a salt thereof.
The present invention also provides pharmaceutical compositions comprising a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof. The pharmaceutical compositions of the present invention are useful an agents for suppressing cancer metastasis or a agents for suppressing cancer proliferation. The pharmaceutical compositions of the present invention are also useful agents for preventing or treating cancer.
The pharmaceutical compositions of the present invention are also useful agents for regulating a function of the pancreas. The pharmaceutical compositions of the present invention are especially useful agents for preventing or treating acute or chronic pancreatitis or pancreatic cancer.
The present invention also provides pharmaceutical compositions comprising a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof, which are useful agents for regulating functions of the placenta.
The present invention also provides phannaceutical compositions comprising a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof, which are useful agents for preventing or treating cilia cancer, hydatid moles, invasive moles, miscarriage, fetal hypoplasia, sugar dysbolism, lipid dysbolism or labor induction.
The present invention also provides a method for suppressing cancer metastasis or suppressing cancer proliferation in a mammal which comprises administering to the mammal an effective amount of a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides a method for preventing or treating cancer in a mammal which comprises administering to the mammal an effective amount of a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides a method for regulating a function of the pancreas of a mammal, which comprises administering to a mammal an effective amount of a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides a method for preventing or treating acute or chronic pancreatitis or pancreatic cancer in a mammal, which comprises administering to a mammal an effective amount of a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides a method for regulating a function of a placenta of a mammal which comprises administering to the mammal an effective amount of a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides a method for preventing or treating cilia cancer, hydatid mole, invasive mole, miscarriage, fetal hypoplasia, sugar dysbolism, lipid dysbolism or labor induction in a mammal which comprises administering to the mammal an effective amount of a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides an agent for suppressing cancer metastasis or an agent for suppressing cancer proliferation comprising a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides an agent for preventing or treating cancer comprising a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides an agent for regulating a function of the pancreas of a mammal comprising a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides an agent for preventing or treating acute or chronic pancreatitis or pancreas cancer comprising a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides an agent for regulating a function of placenta comprising a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.
The present invention also provides an agent for preventing or treating cilia cancer, hydatid mole, invasive mole, miscarriage, fetal hypoplasia, sugar dysbolism, lipid dysbolism or labor induction comprising a metastin derivative (I) as defined above, or a salt thereof or a pro-drug thereof.